From the Glyph Overview window we double-click on the cell with the caption "A". Now we see the corresponding Glyph Edit window. Choose Contour in the Insert menu. During this operation a left mouse-click creates a point onto the contour and a right mouse-click creates a point off the contour (used to create a Bézier curve).
Press the Apply button (or click on the first point) to finish the contour. We create two contours in order to complete the glyph.
Contours that need to be filled black must have a clockwise direction. If we want to make a white area inside an existing contour we must make the direction of the new contour counter clockwise.
The contours should stay within the visible area, this area is defined by the two black horizontal lines and the left and right bearings (vertical dashed lines). Make sure the glyph is within this area, parts outside this area will most likely be invisible. The left and right bearings can be changed by dragging them to their desired position. The glyph should be positioned between these lines, otherwise characters will overlap each other.
We close the Glyph Edit window to return to the Glyph Overview window.